1. Technical Field
The present invention is related to a driving circuit of a matrix device, a matrix device, an image display device, an electrophoretic display device, and an electronic apparatus.
2. Related Art
Matrix devices, which include functional elements arranged in a matrix, and which sequentially select these functional elements to fulfill a predetermined function, are used in various devices. For example, they are used in image display devices such as electrophoretic display devices, liquid crystal displays, EL display devices and the like, or various devices such as capacitance detection devices which are components of finger print sensors and the like.
The matrix device is provided with a driving circuit connected to the functional elements via lines. For example, the image display device is provided with a scan line driving circuit which inputs selection signals to the pixels used as the functional elements, and a data line driving circuit which inputs image signals to the pixels. Further, in the data line driving circuit, a plurality of systems (a dot-sequential system, a line-sequential system, a block sequential system and the like) are also adopted according to usage.
Among the plurality of systems of the data line driving circuit, the line-sequential system is a driving system suitable for an image display device since it can secure long signal input time as compared with other systems (see JP-A-2006-119409). Here, FIG. 12 is a view showing a portion of the line-sequential system of the data line driving circuit. A data line driving circuit 300 includes a shift register 310, a first data latch circuit 311, a second data latch circuit 312, and a data buffer circuit 313.
In the data line driving circuit 300, latch circuits of the first data latch circuit 311 are activated by selection signals SEL[0] to SEL[2] sequentially output from the shift register 310 and image signals D1 to D3, which are supplied via corresponding data signal lines 315, are written to each of the latch circuits. After the writing to the first data latch circuit 311 is finished, a latch activation signal LAT is input to the second data latch circuit 312 via a latch control line 317. Herewith, the output (image signal) of the first data latch circuit 311 is transferred to the second data latch circuit 312. The image signals output from the second data latch circuit 312 are then output all at once with respect to all data lines 68 via a data buffer circuit 313. In accordance with the above-described operation, the image signals are input to the pixels 40 of the display section 5.
However, the image display device including the line-sequential system of the data line driving circuit is constituted so that if the latch activation signal LAT is input, all the latch circuits constituting the second data latch circuit 312 operate all at once, and the image signals are output all at once to all data lines 68. At this time, since a large current is caused to instantaneously flow in the data buffer circuit 313, a voltage drop in the power supply occurs. When the power supply of the image display device then suffers from a low performance of the power supply, such as a button battery or the like, there is a danger that a case may occur where power is cut off one time and restored, thereby initializing the device.